PROJECT DESCRIPTION: Extant research indicates that lesbian, gay and bisexual (LGB) individuals are at heightened risk for substance use disorders (SUD), and that sexual minority discrimination and accumulated life stresses may be etiologic to SUD; however, few studies have attempted to study these factors among sexual minorities. This proposal, Discrimination, Stress and Substance Use Disorder among Sexual Minority Adults: A Secondary Analysis of NESARC-III addresses the dearth in research regarding sexual minorities, and responds to PAR-16-234, Accelerating the Pace of Drug Abuse Research Using Existing Data. In 2015, the NESARC-III data became available for secondary analysis and includes the largest, nationally representative sample of LGB individuals and the most comprehensive measures of SUD, and heterosexual and LGB sexual orientation. The NESARC-III includes: a) a large sample of heterosexual and LGB individuals for general and subsample comparisons; b) a measure of sexual orientation that allows for an assessment of SUD and discordant orientation within three dimensions of sexual orientation (attraction, behavior, identity); c) valid and reliable measures of sexual minority discrimination (distal/institutional and proximal/individual), childhood stress, accumulated stress, quality of life and health, treatment seeking and recovery; and d) substance use measures that align with the new DSM-5 criteria for SUD and other psychiatric disorders. The NESARC-III is the only large-scale nationally representative survey that allows for a psycho-social and epidemiological examination of LGB and heterosexual individuals, and SUD based on DSM-5 diagnostic criteria. Guided by Meyer's Minority Stress Model and using NESARC-III data, we test our proposed model, the Sexual Minority Stress Model (SMStM): Aim 1: Assess prevalence of: a) substance use disorders (DSM-5 diagnosis) including severity level (mild, moderate and severe); b) specific drug use disorders (e.g., DSM-5 cannabis disorder); c) psychiatric comorbidities associated with substance use disorders (DSM-5 diagnosis); and d) recovery/remission from substance use disorders based on attraction, behavior, and identity. Examine variations by sex, age, birth cohort, race/ethnicity. Aim 2: Evaluate the extent to which our proposed SMStM is evidenced in the NESARC-III data: a) We will determine if the overall measurement model provides a better model fit for sexual minorities when compared to heterosexuals; b) We will determine if model fit improves for sexual minorities when measures for individual and institutional sexual minority discrimination are included; c) We will assess differences in model fit across birth cohorts. Aim 3 We will evaluate the extent to which sexual orientation discordance contributes to our understanding of SUD in the context of the SMStM for all respondents, and by sexual minority status. It is hypothesized that sexual discordance (i.e. mis-alignment of respondents' sexual identity with their sexual attraction, behavior, or both) will be associated with SUD outcomes for all heterosexual and LGB respondents. We will assess differences across birth cohorts.